CN1221819C - Effective use of light apparatus and methods from aperture lights - Google Patents

Abstract

The present invention relates to lamp systems that efficiently use light from an aperture lamp. The lamp systems are each configured to accomplish various types of light recovery, including etendue recycling, polarization recycling, and/or color recycling. Various novel optical elements are disclosed, including an electrodeless light source bulb having an integral lens, a molded quartz ball lens having an integral flange, a molded quartz CPC having an integral flange, a truncated CPC and a segmented CPC. Various novel optical systems are also disclosed, including systems that accomplish angle selection and/or etendue selection.

Description

Effective use of light apparatus and methods from aperture lights

Certain inventions described herein were made with Government support under Contract No. DE-FC26-99FT40635 awarded by the Department of Energy. The government has certain rights in these inventions.

field of invention

Aspects of the invention generally relate to lamp systems that advantageously employ from aperture lamps. Certain aspects of the invention relate to novel structures capable of returning a portion of the light emitted from the aperture back into the aperture for absorption and re-emission by the plasma of the lamp.

Background of the invention

The present invention generally relates to the types of lamps disclosed in US Patent Nos. 5,773,918 and 5,903,091, each of which is incorporated herein by reference in its entirety. The '918 and '091 patents each disclose various lamp configurations for beneficial use of waste lamps.

Summary of the invention

Many of the inventions described herein advantageously employ light from lamps described in co-pending PCT application No. PCT/US00/16302, filed June 29, 2000, publication number WO99/36940. description, the entire content of which application is hereby incorporated by reference.

According to one aspect of the present invention, there is provided a projection system comprising: a light source; an image aperture illuminated by the light source; and a shutter that is selectively opened and closed to project an image from the image aperture, wherein according to Opening and closing of the shutter modulates the light source, which is modulated synchronously with the shutter such that when the shutter is open a light output of the projected image is produced and when the shutter is closed a light output less than that of the projected image is produced.

On the basis of the above projection system, the light source is an electrodeless light source.

On the basis of the projection system described above, the light source is an arc lamp.

On the basis of the above projection system, the image projected from the image aperture comes from a liquid crystal device.

On the basis of the projection system described above, the modulation frequency corresponds to the image frame frequency.

According to another aspect of the present invention, there is provided a method of operating a projection system, the method comprising:

providing light from a light source; illuminating an image aperture with light from the light source; changing the state of a shutter between open and closed to project an image from the image aperture; and, modulating the light source according to the state of the shutter; modulating the light source includes: when the shutter providing a light output from the light source to project an image when in an open state; and providing a weaker light output from the light source than the light output to project an image when the shutter is in a closed state.

On the basis of the method of operating the projection system described above, the closed state of the shutter corresponds to the closed state between image frames.

On the basis of the method of operating the projection system described above, the image projected from the image aperture comes from the liquid crystal device.

On the basis of the above method of operating a projection system, modulating the light source includes: modulating the light source at a frequency corresponding to an image frame rate.

According to one aspect of the present invention, a lamp system includes: a housing containing a fill capable of recycling light; and an optical element spaced from the housing and configured to direct light emitted from the housing to the Light outside the desired angle is reflected back into the housing, recycled through the fill, while allowing light within the desired angle, where the output light is stronger than without the optic, to pass through, The desired angle is selected based on the uniformity and angular distribution of the light from the housing.

According to another aspect of the present invention, a lamp system includes: an envelope containing a fill capable of recirculating light; and a high temperature wire grid polarizer spaced proximate to the envelope and configured to have no Light of the desired polarity is reflected back into the housing to be recycled through the fill while allowing light of the desired polarity to pass, wherein the wire grid polarizer is capable of withstanding an operating temperature of at least about 400°C.

According to another aspect of the present invention, a lamp system includes: a housing containing a filling capable of recirculating light; an optical element forming an opening corresponding to a desired angle relative to the housing; High temperature wire grid polarizers where the optic aperture area is spaced adjacent to the optic, where the optic is spaced from the housing and configured to reflect light outside the desired angle back into the housing for recycling through the fill and polarized light The light source is configured to reflect light having an undesired polarity back into the housing for recycling through the fill, whereby light emitted from the lamp system is within a desired acceptance angle and has the desired polarity with a light output ratio of The light output is stronger without optics and polarizers. For example, a polarizer is disposed in the aperture formed by the optical element. In another example, the polarizer is planar, and the system further includes a lens disposed between the polarizer and the bulb, wherein the lens increases the amount of light reflected by the polarizer back into the housing.

According to another aspect of the present invention, an optical device includes: a plurality of optical fibers defining interstitial spaces between the optical fibers; and a reflective material selectively disposed on the interstitial spaces.

According to another aspect of the present invention, a method of manufacturing a screen on an optical device comprising a plurality of optical fibers forming interstitial spaces between the optical fibers comprises: The photosensitive material is provided; the other end of the fiber optic device is illuminated with a suitable light to photosensitive the material; and, the photo-stimulated or non-photo-stimulated material is removed to provide the desired barrier film.

According to another aspect of the present invention, a lamp system includes: a housing containing a filler capable of recycling light; and an optical fiber bundle having a plurality of optical fibers forming interstitial spaces and selectively A reflective material disposed over the void space, wherein the reflective material reflects at least that light that does not enter the fiber back into the housing, is recycled through the filler.

According to another aspect of the present invention, a lamp system includes: an envelope containing a fill capable of recirculating light; a reflective material enclosing the envelope except for the open area from which light emerges; An optical element that is light-aligned with the housing and that is adjacent to, but separated from, the housing, where the optical element has an anti-reflection coating to transmit light within a desired angular distribution and reflect back light outside the desired angular distribution to the enclosure for recirculation.

According to another aspect of the present invention, a lamp system includes: a housing containing a fill capable of recirculating light; and, an optical element aligned with light exiting the housing, wherein the optical element includes a The reflective structure of , wherein the reflective structure constitutes a plurality of light exit apertures, wherein the optical element and the reflective structure are configured together to guide light that does not pass through the plurality of light exit apertures to the housing for recycling.

According to another aspect of the present invention, a lamp system comprising: a housing encased in reflective ceramics except for the region of the aperture from which light emerges; and an optical element adjacent the aperture along the optical axis, wherein The aperture area increases away from the optical axis of the bulb 133, whereby the optical access to the bulb can be larger and the optical elements can be positioned relatively closer to the bulb than with an aperture of constant area.

According to another aspect of the present invention, a lamp system includes: a housing encased in reflective ceramics except for the region of the first opening; and a hollow optical element with its input end against the encased housing Positioning, wherein the surface contacting the input end of the enclosed housing is reflective, wherein the input end constitutes a second opening, the inner perimeter of the second opening is inward of the perimeter of the first opening, so that the second opening constitutes The opening of the housing for emitting light.

According to another aspect of this aspect, a lamp system comprising: a housing; a light rod integrally connected to the housing; and a reflective ceramic material covering the housing except for the area where the light rod is connected to the housing, wherein the reflective ceramic material is in the The junction of the proximity housing and the polished rod is beveled to avoid distracting light entering the polished rod.

According to another aspect of the present invention, an electrodeless light bulb includes: a body portion; and an optic portion integrally connected to the body portion, wherein the body portion and the optic portion together form a sealed interior volume. For example, the optics include a truncated spherical lens forming a flat entry surface within the sealed interior volume of the bulb.

According to another aspect of the present invention, a high temperature monolithic optical element comprises: an optical part; and, a positioning part combined with the optical part, wherein the positioning part does not interfere with the operation of the optical part, wherein the two Partially made of a one-piece construction of a suitable material to withstand an operating temperature of at least 400°. For example, the optical portion includes a truncated spherical lens and the positioning portion includes a flange on the entry surface of the spherical lens, both portions being made of molded quartz. In another example, the optical part comprises a CPC (Compound Parabolic Concentrator), the positioning part is a flange on the exit surface of the CPC, and the two parts are made of molded quartz.

According to another aspect of the invention, an optical element includes a plurality of frusto-conical portions having angled steps, having a rectilinear cross-section and adapted to approximate a curvilinear cross-section.

According to another aspect of the invention, an optical element includes a circular input surface and an output surface, the output surface being truncated from a circle to a more rectangular surface having four sides substantially perpendicular to the output surface.

According to another aspect of the invention, an optical element comprises four segments connected to each other along respective edges, each of which corresponds to a small portion of the CPC and maintains the curve of the CPC to provide the desired angular transformation while providing a More rectangular output.

According to another aspect of the present invention, an optical system includes: an input diaphragm and an output diaphragm aligned along an optical axis and configured to suppress passing light to a desired range of angles; and an optical element positioned adjacent the output diaphragm, And can bend the edge rays inwardly with respect to the optical axis, while leaving the inner rays unchanged.

According to another aspect of the present invention, a lamp system includes: a housing containing a recyclable fill and covered with a reflective ceramic material except in the area of the first opening; and a reflector, and The housing is spaced apart and forms a second aperture aligned with the first aperture along the optical axis, and the reflector can reflect light from the first aperture impinging outside its second aperture area back to the first aperture to Recirculation, wherein the distance of the first opening to the second opening and the relative size of the second opening relative to the first opening are selected according to the target etendue.

According to another aspect of the invention, a lamp system includes: a housing containing a recyclable fill and covered with reflective ceramic material except for an open area; an angle-selective optic adjacent the housing, and can transmit light within a desired range of angles and reflect light outside the desired range back to the housing for recycling; an integrator that accepts light from the angle selector; and an angle conversion optic that can Receive light from the integrator. In some examples, the angle selecting optics, integrator, and angle converting optics are hollow and fabricated integrally with each other. In another example, the angle selecting optics, integrator, and angle converting optics are separate components and various mechanical features are used to position these components relative to each other.

According to another aspect of the present invention, an optical device includes: a polarizing cube adapted to receive light on an input surface and transmit light of a first polarity along a first optical axis through a first output surface and reflect a second polarity polarity of light through the second output surface; a polarization rotator, located near the second output surface, to change the second polarity of light to the same polarity as the first polarity; The light of the polarization rotator is directed in the same direction as the light transmitted through the first output surface.

According to another aspect of the present invention, an optical tube includes: a lens tube that can accommodate and fix a lens therein; a first flange connected to the input end of the lens tube, and the first flange is formed with a structural member that can be connected with Corresponding parts on the apertured lamp match to provide optical alignment along the optical axis; and, a second flange connected to the output end of the lens tube, the second flange is formed with a structural member that can be matched with the optical alignment on the housing. Corresponding parts match, whereby the apertured light maintains proper alignment to deliver light into the housing.

According to another aspect of the present invention, a lamp system includes: an RF (radio frequency) excitation light source; a lens tube mounted on the RF excitation light source; The light source reduces EMI (Electromagnetic Interference). For example, the RF choke includes a conductive mesh.

According to another aspect of the present invention, a light system includes: an enclosure having a length, width, and depth, wherein the depth is substantially less than either the length or the width; an apertured lamp positioned to direct light into the interior of the enclosure; and, a A lens system to receive light from the apertured lamp and shape the light output to more evenly distribute within the enclosure. For example, the housing includes a standard 2x2 or 2x4 groove, where the lens system includes a cylindrical lens positioned to reduce the angular range of light in one dimension relative to depth.

According to another aspect of the present invention, a projection system includes: an electrodeless light source; an image aperture illuminated by the electrodeless light source; and a shutter selectively opened and closed to project an image from the image aperture, Wherein the electrodeless light source can be modulated according to the opening and closing of the shutter.

The foregoing and other features and aspects of the invention can be achieved individually or in combination. The invention is not to be read as requiring two or more of these features unless expressly recited in the claims.

Brief description of the drawings

The above and other objects, features and advantages of the present invention can be clearly understood from the following more specific description of preferred embodiments with reference to the accompanying drawings, wherein the same parts are denoted by the same reference numerals in all the drawings. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.

Fig. 1 is a cut-away schematic diagram of a lamp system for etendue recycling according to the present invention.

Figure 2 is a graph of the angular distribution of light for an aperture lamp compared to a Lambertian distribution.

Figure 3 is a graph of light intensity versus beam angle for a lamp system with no conditioned output, conditioned output without recirculation, and conditioned output with etendue recirculation.

Figure 4 is a schematic cut-away view of a lamp system according to the present invention employing a high temperature wire grid polarizer to recycle polarized light.

Figure 5 is a schematic cut-away view of a lamp system of the present invention utilizing both etendue and polarized light recycling.

Fig. 6 is a fragmentary perspective view of the first optical fiber bundle of the present invention.

Fig. 7 is a schematic partial cross-sectional view of a lamp system employing an optical fiber bundle according to the present invention.

8A to 8D are schematic cross-sectional views of process steps for manufacturing an optical fiber bundle according to the present invention.

9A to 9D are schematic cross-sectional views of another process step for fabricating an optical fiber bundle according to the present invention.

Fig. 10 is a schematic cross-sectional view of a second optical fiber bundle of the present invention.

Fig. 11 is a perspective view of a third optical fiber bundle of the present invention.

Fig. 12 is a schematic partial cross-sectional view of a lamp system employing a microlens array according to the present invention.

Figure 13 is a partial cross-sectional view of a lamp system employing a chamfered aperture.

FIG. 14 is an enlarged fragmentary view of the chamfered opening of FIG. 13 .

Figure 15 is a cross-sectional view of a lamp system employing optical elements to confine a spherical aperture.

Figure 16 is a cross-sectional view of a lamp system employing an angle-selective coating.

17 is a schematic cross-sectional view of the remote aperture light system of the present invention.

18 is a schematic cross-sectional view of another remote aperture light system of the present invention.

19-24 are perspective views of different optical elements and remote aperture structures of the present invention, respectively.

Figure 25 is a diagram of an optical system capable of providing a planar source of polarized light.

Fig. 26 is a cross-sectional view of a lamp system employing the light system of Fig. 25 .

Figure 27 is a cross-sectional view of a jacketed bulb with an integral polished rod.

Figure 28 is a cross-sectional view of a jacketed bulb with an integral polished rod, with the spherical jacket cut at a bevel.

Figure 29 is a cross-sectional view of an electrodeless light bulb with an integral lens.

Fig. 30 is a cross-sectional view of an apertured lamp using the bulb of Fig. 29 .

Fig. 31 is a schematic diagram of a spherical lens.

Figure 32 is a schematic illustration of a molded spherical lens according to the first aspect of the invention.

Figure 33 is a schematic front view of a molded spherical lens.

Fig. 34 is a sectional view of a mold for manufacturing a molded spherical lens.

Fig. 35 is a cross-sectional view of another mold for manufacturing a molded spherical lens.

Figure 36 is a schematic illustration of a molded CPC with an integral flange.

Figure 37 is a cross-sectional view of a molded CPC.

Figure 38 is a perspective view of a molded TLP with an integral flange.

Figure 39 is a cross-sectional view of a molded TLP.

Figure 40 is a schematic illustration of a tapered light cone with angled steps.

Figure 41 is a schematic diagram of a tapered light cone with a lens.

42-44 are schematic left, front and bottom views, respectively, of a CPC.

45-47 are schematic top, front and right side views, respectively, of a truncated CPC taken along the dashed lines of FIGS. 42-44.

Figure 48 is a front view of a truncated CPC equipped with a remote port.

Figure 49 is a perspective view of a segmented solid CPC.

Figure 50 is a perspective view of a segmented hollow CPC.

51 is a schematic diagram of a curved edge-ray optics system according to one aspect of the invention.

Figure 52 is a schematic diagram of another optical system that bends edge rays.

Figure 53 is a schematic cut-away diagram of a lamp system employing etendue selection methods in accordance with one aspect of the present invention.

54 is a cross-sectional view of a lamp system employing an angle selection method and an integrator according to one aspect of the present invention.

55-59 are schematic cross-sectional views of other optical structures of the lamp system shown in FIG. 54, respectively.

FIG. 60 is an enlarged view of area 60 in FIG. 59 .

Figure 61 is a schematic diagram of an example of a light system according to an aspect of the present invention.

Fig. 62 is a schematic diagram of another example of an optical system according to an aspect of the present invention.

63 is a schematic diagram of yet another example of a light system according to an aspect of the present invention.

Figure 64 is a schematic diagram of a projection system according to an aspect of the present invention.

65 is a schematic diagram of a lamp system employing a polarizer cube according to another aspect of the invention.

66 is a schematic diagram of a lamp system employing a polarizer cube according to another aspect of the invention.

67-69 are schematic top, left and right side views, respectively, of an optical holder according to an aspect of the present invention.

Figure 70 is a front schematic view of an apertured light bulb suitable for use with an optical holder.

71-72 are schematic left and top views, respectively, of a lens tube according to an aspect of the present invention.

Figure 73 is a schematic illustration of an RF screen suitable for housing in a lens tube.

Figure 74 is an enlarged partial cross-sectional view of an RF screen installed in a tube.

Figure 75 is a perspective view of a housing for a light box of an aspect of the present invention.

Figure 76 is a perspective view of a lens used in a light box.

Fig. 77 is a partial sectional view of the light box.

Detailed Description of the Invention

In the following description, for purposes of illustration rather than limitation, specific details are cited, such as specific structures, interfaces, processes, etc., in order to provide a comprehensive understanding of the present invention. It will be appreciated, however, by those skilled in the art that the benefit of this disclosure may allow the invention to be employed in other embodiments that depart from these specific details. In certain instances, descriptions of well-known devices and methods are omitted so as not to obscure the description of the present invention.

Etendue recycling

According to the present invention, an increased amount of light is delivered to the desired etendue from an apertured lamp, such as that described in PCT Publication No. WO99/36940 cited above. In some applications, such as projection systems, an important performance parameter is the luminous flux delivered to, for example, an optical imaging element with a given area and angular acceptance, in this paper etendueε is defined as:

ε＝π×(area)×sin ² (θ)

where θ represents the half-angle of the cone for a particular ray.

A three-dimensional light source, such as a conventional arc lamp, employs an external reflector to redirect and focus the light on the desired object or plane, with attendant losses due to collection efficiency and other factors. Furthermore, an arc lamp generally provides only localized bright spots, with most of the luminous flux of the source being emitted from various, barely bright discharge portions.

The aperture lamp of the '940 publication aims to solve most of the above problems by providing a two-dimensional light source with a very uniform light output. A spherical lens is placed in contact with the lamp opening, after which suitable lenses are used to provide light with the desired beam angle. However, the present invention demonstrates the potential for further improvements.

Figure 2 shows the actual light distribution from an apertured lamp. As shown in Figure 2, for larger angles, the light output decays faster than the Lambertian cos(θ) curve. A Lambertian optical distribution has constant brightness. In other words, the brightness seen from any angle will be the same. As a result, any corner of the Lambertian source produces the same brightness. Light increases or decreases at the same rate as etendue.

However, for sub-Lambertian light sources, there is less light at large angles. The lens structures disclosed in the '940 publication introduce these angles into the transmitted light, and thus increase etendue proportionally greater than the light they increase. According to one aspect of the invention, light outside a desired angle is reflected back into the lamp to reduce the effect of sub-Lambertian light output on etendue. According to another aspect of the invention, the size of the lamp aperture is increased to suppress output angles, the larger lamp aperture area matches the target etendue. While there is a significant increase in the amount of output light, increasing the aperture size has the effect of slightly reducing the peak forward directed brightness, a difference that indicates an increase in the amount of light directed at the target etendue.

A lamp system capable of etendue recycling employs a spherical lens having a reflective outer surface forming an aperture. Light at large angles is reflected back into the lamp, where it passes through the previous integrating sphere, is reabsorbed and re-emitted with a given probability. This results in lower light output, but also lower etendue. The light output can be further increased by increasing the size of the lamp opening.

Figure 1 is a schematic cross-sectional view of a preferred lamp system for etendue recycling. An aperture lamp 3 comprises a bulb 5 arranged in a ceramic envelope 7 . The bulb 5 is positioned against a front ceramic washer 9 constituting a first opening 11 . The space within the housing 7 not occupied by the bulb 5 is filled with a reflective ceramic material 13 . A rear ceramic disk 15 is located in the cover 7 behind the reflective material 13 . Further details regarding the construction of the apertured lamp 3 are referred to the '940 publication.

The spherical lens 17 is located in front of the opening 11 for reducing the beam angle of the light emitted from the opening 11 . The optical element 19 is spaced apart from the spherical lens 17 and forms a second opening 21 corresponding to the angle required for the light to pass, wherein the angle is constituted with respect to the optical axis of symmetry. The reflective surface 23 of the optical element facing the aperture 11 is configured to return at least part of the light outside the desired angle back into the bulb 5 where it can be absorbed and re-emitted by the plasma. For example, a photon traveling along path A leaves spherical lens 17 along path B, where the photon encounters optical element 19 and returns to bulb 5 along path C. There is a non-zero probability that a portion of the returning excess light will re-emit and exit the first aperture 11 through the second aperture 21 within the desired angle, thereby increasing the intensity of the light passing through the aperture 21 .

In the preferred embodiment shown in FIG. 1, the spherical lens 17 has a first radius R1, and the optical element 19 has a second radius R2 which is larger than R1. The spherical lens 17 and the optical element 19 do not share the same center. However, their respective center points C1, C2 are aligned along a common optical axis represented by centerline _CL . The optical element 19 is configured such that its center point C2 is located inside the bulb 5 , preferably close to the opening 11 , so that most of the light reflected by the optical element 19 is transmitted into the bulb 5 through the opening 11 .

Figure 3 shows a graph of light intensity versus beam angle for a lamp system with unrestricted output, with reconditioned output without recirculation, and with recirculated etendue with recirculated output. From the graph it is clear that simply limiting the output (for example with a non-reflective aperture stop) does not increase the intensity, only narrows the beam angle of the light. However, with etendue recirculation according to the invention (for example with the embodiment of FIG. 1 ), not only is the beam angle reduced, but the light intensity is also significantly increased.

High temperature polarized light recycling

As noted in the aforementioned '091 patent, light of an undesired polarity can be advantageously recycled by certain lamp plasmas such as sulfur, selenium, tellurium, indium halides, and other metal halides. Conventional optical elements used for these recyclings include optical films such as Double Sided Brightness Enhancement Film (DBEF) manufactured by 3M Company. These membranes are generally made of plastic and cannot withstand high temperatures. In addition, these films degrade under UV light, thereby limiting the lifetime of optical systems employing these films under broad-spectrum light.

4 is a schematic cross-sectional view of a lamp system of the present invention employing a high temperature wire grid polarizer to recycle polarized light. The aperture lamp 33 is similar to the aperture lamp 3 and comprises a bulb 35 arranged in a ceramic cover 37 . The bulb 35 is positioned against a front ceramic gasket 39 forming the opening 41 . The space within the housing 37 not occupied by the bulb 35 is filled with a reflective ceramic material 43 . A rear ceramic disk 45 is located within the cover 37 behind the reflective material 43 .

According to one aspect of the invention, a wire grid polarizer 46 is located directly in front of the aperture 41 . A spherical lens 47 is positioned opposite the polarizer 46 on the opposite side of the polarizer 46 to the aperture 41 . The lamp system may also include an optional clear polarizer 49 disposed on the curved outer surface of the spherical lens 47 in FIG. 4 .

Wire grid polarizer 46 is configured to pass light of a desired polarity and reflect light of an undesired polarity back into bulb 35 through aperture 41 . The returning light has a non-zero probability of being absorbed by the fill and re-emitted of the desired polarity, thereby increasing the useful light output. One advantage of the wire grid polarizer 46 is that it is made of high temperature materials (eg, metal and glass) and can withstand high operating temperatures (eg, at least about 400°C). Suitable wire grid polarizers are commercially available including, for example, Moxtek of Orem, Utah.

Depending on the particular lamp construction, the temperature directly in front of the opening 41 may still exceed the maximum operating temperature of the polarizer 46 . In this case, the polarizer 46 can be omitted and replaced by a clear polarizer 49 as the main polarizer of the lamp system. Polarizers 46 and 49 can be made integral with ball lens 47 or as a separate piece.

Etendue and polarized light recycling

Fig. 5 is a cut-away schematic diagram of a lamp system using etendue recirculation and polarized light recirculation according to the present invention. An aperture lamp 3 is the same as described in FIG. 1 . The spherical lens 17 is located in front of the apertured lamp 3 and the optical element 19 is separate from the apertured lamp 3 . The wire grid polarizer 51 is disposed in the second opening 21 formed by the optical element 19 .

In operation, at least a portion of the light outside the desired angle formed by the aperture 21 is reflected back to the bulb 5 through the aperture 11, and at least a portion of the light within the desired angle but without the desired polarity is also passed through the aperture. 11 is reflected to bulb 5. Thus, the light exiting the lamp system through aperture 21 is both within the desired angle and has the desired polarity. A portion of the light returning to the bulb is recirculated through the plasma and exits the lamp system within the desired angle, again with the desired polarity, thereby increasing the output of useful light.

Advantageously, the polarizer 51 is sufficiently separated from the apertured lamp 3 to maintain the operating temperature of the polarizer at a suitable operating temperature, generally well below its specified maximum operating temperature. Furthermore, the material of the wire grid polarizer 51 does not degrade significantly under ultraviolet light, thereby not limiting the lifetime of the lamp system.

Yet another advantage of the combined etendue/polarized light recirculating lamp system is that properly constructed optics 19 along with wire grid polarizer 51 can reduce electromagnetic interface (EMI) leakage. Optical element 19 and polarizer 51 may be made of conductive material. For example, the optical element 19 may consist of mirrors made of silver and the wire grid polarizer 51 may consist of an array of metal wires. According to one aspect of the invention, optical element 19 and polarizer 51 are incorporated into a lens tube also made of a conductive material such as aluminum, all electrically connected together and grounded to form an effective EMI shield.

Effective Combination of Light and Optical Fiber

According to one aspect of the present invention, a lamp system is configured to more efficiently couple light from an aperture lamp into a fiber optic bundle having interstitial spaces between individual fibers. Such void spaces may be "dead spaces" caused by, for example, the metal cladding surrounding the individual fibers. In conventional lamp systems, light from the lamp that passes through the void space is not then transmitted in the fiber and is lost as waste light. This void space accounts for 15-40% of the fiber bundle and thus represents a significant loss of light.

According to the invention, this problem is overcome by depositing a reflective layer on the interstitial area of the receiving surface of the fiber bundle, while keeping the individual fiber surfaces out of contact. The light reflected from the void area is then sent back into the active lamp volume, a portion of which is recycled and re-ejected. Re-exited light has a non-zero probability of penetrating and entering the active fiber surface, as does light conducted by the fiber. The reflective void space effectively becomes part of the reflective envelope of the apertured lamp. Similarly, the sum of the individual fiber apertures then represents the effective aperture area of the lamp, which is preferably taken into account when constructing apertured lamps.

Fig. 6 is a partial perspective view of the first optical fiber bundle of the present invention. Fiber bundle 61 includes a plurality of individual optical fibers 63 . Each optical fiber 63 forms an interstitial space between them, and a reflective material 65 is disposed over the interstitial space.

Figure 7 is a schematic partial cross-sectional view of a lamp system utilizing fiber optic bundles in accordance with the present invention. The aperture lamp 62 comprises a bulb 64 covered by a reflective ceramic 66 forming an aperture 67 . The lamp system is configured such that one end of the optical fiber bundle 61 is provided with a reflective material 65 , which end is provided adjacent to the opening 67 . Photons emitted from the plasma 68 exit the aperture along path A into individual fibers 63 and are transmitted through the fiber. Photons exiting the plasma 68 exit the aperture along path B to encounter the reflective material 65 and return to the plasma 68 where they are absorbed by the plasma 68 before exiting into one of the respective fibers 63 with non-zero probability.

Advantageously, the optics of the fiber bundle facilitate a variety of processing methods suitable for depositing the reflective layer on the void space. One such method is described below.

Photosensitive surface chemistry is well known in the art of pattern (pattern) metallization. In such methods, a thin-film photosensitive layer is deposited on the surface of the object. The film is then exposed to a patterned image of light capable of altering the chemical activity of the photosensitive layer in the areas exposed to this light. The exposed surface is then developed with other chemicals to remove the original photosensitive layer in those exposed areas and selectively deposit a thin-film metallic reflective layer in those areas that were not exposed. Exposing the area covering the active fiber surface is as simple as exposing the other surfaces of the fiber bundle to the light necessary to photosensitize the film.

8A to 8D are schematic cross-sectional views of steps in a method of manufacturing an optical fiber bundle according to the present invention. FIG. 8A shows an initial fiber optic bundle 71 comprising a plurality of individual fibers 73 and interstitial material 74 . In FIG. 8B , a photosensitive adhesive layer 77 is deposited on one end of the fiber bundle 71 and the other end of the fiber bundle 71 is exposed to suitable light 79 to activate the adhesive layer 77 . In fact only the areas of layer 77 which overlap the individual fibers 73 are exposed to light. As shown in FIG. 8C , after further processing, an adhesive layer 77 remains that corresponds to the region overlapping the void region 74 . Finally, as shown in FIG. 8D, a metalized reflective layer 75 is selectively deposited on the remaining adhesive layer 77. Referring to FIG.

There are a number of other methods that can be used to selectively convert void regions in fiber bundles into reflective surfaces. The above method is an additive method, that is, the reflective material is selectively added to the void space. A selective subtractive method can also be used, that is, the initial film photosensitive adhesive layer is left on the fiber end surface and removed from the space area, and then the entire surface is coated with a reflective material, which can be well bonded to the future. coating the photosensitive layer over the voided areas; the resulting surface is then exposed to an etchant which attacks the underlying developed photosensitive material on the active fiber end face, but which does not attack the reflective coating on the voided material. This selection can be achieved, for example, with an organic photosensitive material and an inorganic reflective layer (which can be metallic or dichroic).

9A to 9D are schematic cross-sectional views of further method steps for manufacturing the optical fiber bundle of the present invention. In FIG. 9A, the fiber bundle 81 has a layer of organic material 87 that is photo-stable deposited on one end surface of the fiber bundle. The other end of the fiber optic bundle 81 is exposed to suitable light 89 to stabilize the material 87 . As shown in FIG. 9B , after further processing, the remaining material 87 is the material that overlaps with the fibers 83 , while the material that is removed is the material that overlaps with the void material 84 . In FIG. 9C , a directionally deposited reflective layer 85 is applied to the fiber bundle 81 . In FIG. 9D, a solvent is used to selectively remove the organic layer 87 and the reflective material 85 deposited thereon. The remaining reflective layer 85 is equivalent to the reflective material laminated to the void material 84 .

Advantageously, the above two methods use the geometry of the fiber bundle to provide self-alignment facilities for the selective processing of the reflective layer, thereby eliminating the need for additional light-shielding films and simplifying the manufacturing process.

Color recycling

Fig. 10 is a schematic cross-sectional view of a second optical fiber bundle of the present invention. According to one aspect of the invention, the reflective material in the void space, combined with selective wavelength reflection, can recycle more light. In FIG. 10 , an optical fiber bundle 91 includes individual optical fibers 93 and interstitial material 94 . One end of the fiber bundle 91 also includes a total reflection layer 95 laminated with the void material 94, and a selective reflection layer 97 shown in FIG. The reflective layer is at least laminated with the fibers 93 . For example, selectively reflective material 97 may include a red/green/blue dichroic band pass material. In operation, light reaching reflective layer 95 is reflected back to the bulb, and light outside the desired wavelength and reaching reflective layer 97 is selectively reflected back to the bulb for recycling. Depending on processing considerations, the order of selectively reflective layer 97 and reflective layer 95 may be reversed (eg, dichroic material may be on top of metallic material).

Alternatively, use three separate optical fiber bundles to selectively absorb the wavelength bands simultaneously separated from the three openings of the same lamp (one for red, green and blue respectively), while the unused light comes from each Recirculation in the opening. Three separate fibers or fiber bundles can be coated with dichroic bandpass filters for the three desired wavelength bands. Light reflected from each band through the filter is immediately recycled due to the proximity of the filter to the apertured lamp.

In a different form, a large core fiber, a tapered light pipe (TLP) or other light guide can be constructed with a dichroic bandpass filter at the end of the distal guide tube of the aperture lamp. Light outside the desired wavelength is reflected through the fiber/cone/light pipe and through the aperture to enter the lamp. As mentioned above, three separate conduits are available for each of the red, green and blue bands. The fiber/cone/light guide can also be fitted with a polarizing (polarizing) filter at either end to recycle light of an undesired polarity.

Fig. 11 is a perspective view of a third optical fiber bundle of the present invention. A single fiber bundle 101 is configured with respective bandpass filters R, G and B in different geometric regions, thereby separating into respective output windows 103, 105 and 107 for each of the three colors red, green and blue. Light reflected by the filter from each wavelength band is immediately recirculated due to the proximity of the filter to the apertured lamp. A polarizing filter may be applied at the remote windows 103, 105 and 107, thereby further increasing lamp generation efficiency by reflecting light of unwanted polarity back through the fiber for recycling. Fiber bundle 101 may also include reflective material in the void space at the end of its R/G/B band pass filter.

microlens array

Figure 12 is a schematic partial cross-sectional view of a lamp system employing a microlens array according to the present invention. The microlens array 111 includes three lenses 113 , 115 and 117 . One side of each lens 113, 115 and 117 is processed into a beam splitter of total reflection color light, which is defined as "partial opening" for this lens, and each lens is also provided with a wavelength-selective waveband pass filter (such as three colors) in addition. one of) that defines which colors can pass through the lens. The array 111 is positioned adjacent to the bulb 121 in an aperture 123 formed by reflective ceramic 125 surrounding the bulb 121 . The three lenses are on different optical axes, resulting in three separate images, one image corresponding to one color band. Wasted light of each color is recycled into the plasma of the lamp.

The preceding optical system is given by way of illustration, not limitation. With the benefit of this description, many other optical systems may employ aspects of the invention.

Chamfered openings filled with CPC

According to one aspect of the invention, an apertured luminaire has a tapered aperture to allow closer optical access to the overfill optics.

An optical element is said to be underfilled when the entrance surface of the optical element (ie, the surface closest to the aperture lamp) is not fully illuminated by the light source. This phenomenon can occur if the entrance surface is larger than the aperture and the optics are in close proximity to the aperture. For example, the ball lens 17 in FIG. 5 is underfilled relative to the opening 11 . On the other hand, when the entrance surface is completely illuminated by the light source, the optical element is said to be overfilled. This phenomenon occurs when the entrance surface is smaller than the aperture or when the optic is separated from the aperture. For example, fiber optic bundle 61 is overfilled relative to aperture 67 in FIG. 7 .

One problem with certain underfilled optics is the appearance of parallax black circles, which cause undesirable non-uniformity in light output. One problem with overfilling an optical element is light loss beyond the edge of the optical element.

The present invention in this aspect reduces the amount of light lost by overfilling the optical element by beveling the aperture surface to position the optical element closer together.

Referring to Figures 13-14, a lamp system 131 includes a bulb 133 encased in a reflective ceramic 135 except in the area of the light emitting opening 137. A ceramic disc 136 (which may be integral to the apertured lamp) defines an aperture 137 . One surface 138 of disc 136 is obliquely tapered so that the area of the hole on the side of disc 136 contacting bulb 133 is smaller than the area of the hole on the opposite side of disc 136 . In other words, the area of the opening 133 increases along the optical axis as the distance from the bulb 133 increases. This configuration allows for a larger optical path to the bulb 133, allowing the optical elements to be placed closer to the bulb than would be possible with a uniform area opening.

Hollow CPC with reflective entrance surface forming lamp opening

According to one aspect of the invention, a first optical element forms part of the overall volume of the apertured lamp and constitutes the light emission aperture.

As mentioned above, apertured lamps have problems with overfilling or underfilling the optics. The present invention overcomes these problems by using a hollow optical element with a reflective coating on its surface.

Referring to FIG. 15 , a lamp system 141 includes a bulb and a ceramic disc 143 defining an opening 145 . A hollow optical element 147 has a surface 149 positioned relative to the disk 143 and defining an opening 151. According to this aspect of the invention, the outer periphery of the surface 149 is outside the periphery of the opening 145 and the inner periphery of the surface 149 is outside the periphery of the opening 145. Inside the perimeter of 145, surface 149 is adapted to be highly reflective (eg greater than 90%) in at least the viewable area. A portion of the light hits the reflective surface of surface 149 and returns to the plasma from which the light was emitted. Thus, surface 149 forms part of the overall volume of the apertured bulb and aperture 151 provides a light emission opening for the apertured bulb.

Advantageously, the present invention maintains high brightness through optical element 147 due to good spatial and angular uniformity in its light output. A hollow optical element is potentially more efficient in terms of etendue conversion of light. For example, as noted above, a solid optical element must not fill the aperture (ie, overfill it with light). Hollow optics also provide better thermal conduction cooling of the bulb window than solid optics, especially compared to solid optics that cover opening 145 and form a closed insulating space between the bulb and optics. characteristic. Another advantage of the invention in this respect is the loose tolerance between the apertured bulb and the first optical element. Since the optic itself forms the bulb opening, the system is self-aligning and the optic does not need to be precisely centered relative to the bulb.

For example, surface 149 and interior surface 153 of optical element 147 are coated with a high temperature dichroic coating to provide a suitable reflective surface. Depending on the coating process, coating the entire optical element 147 may optionally be more cost effective. Although optical element 147 is illustrated as a CPC, other hollow optical elements may be used including, without limitation, TLPs (tapered light pipes), optical rods or integrators (intrgrators), and spherical reflectors or angle selectors.

Preferably, the hollow optical element 147 has no seams, or as few seams as possible on the inside surface 153 . One method of making optics without inner seams is to shrink a hollow quartz tube around a seamless mold.

Selective High Angle Cutoff

According to one aspect of the invention, high angle light can be removed from the beam and returned to the plasma, with a portion of the returned light re-emitted within the desired beam angle. In this respect, the angle is chosen as close as possible to the plasma from which the light emerges. The selected range of angles may correspond, for example, to the acceptance angle of the optical element. In addition to improving the efficiency of the light source, the invention also improves the utilization efficiency of the light emitted from the opening, because the emitted light is relatively uniform in beam angle.

Referring to Figure 16, the lamp system 154 includes a bulb 155 enclosed in a reflective ceramic 157 except in the area of an aperture 159. An optical element 161 is aligned with the opening 159 along the optical axis. For example, without limitation, optical element 161 may be a CPC, TLP, spherical reflector, a rod or a cone, preferably made of quartz or another high temperature non-conductive material. As shown, optical element 161 represents a right cone of quartz with flat surfaces. The angle-selectable dichroic coating is deposited on the inner bulb surface 163, the outer bulb surface 165, the entrance face 167 of the optic, or the exit face 169 of the optic. For example, the angle selective coating is configured such that light exiting the bulb between angles of +/- 25° relative to the optical axis is highly transmissive in the visible range, or light outside of these angles is highly reflective in the visible range .

Coatings 163-167 on or near the bulb are high temperature dichroic coatings, while coating 169 may be a relatively low temperature coating. Coatings in the area of surfaces 163-167 are generally more effective due to losses from transmission and return from a farther surface 169. A preferred example has no coating 163 or 165 on the surface of the bulb, an angle selective coating on the entrance face 167 of the optical element 161 and an anti-reflection coating on the exit face 169 . The lamp system may also include a remote aperture and/or a reflective polarizer such as DBEF from 3M or the wire grid polarizer described above disposed on or near the exit face 169 . With this configuration, and assuming that the optics 161 and bulb 155 are spaced closer together to reduce light leakage, the area between the optics and the bulb is limited by the amount of light returning from the reflective polarizer and the high angle light cutoff. ) and considerably increases the photon flux density. Properly configured, 50% or more of the light generated will return to the plasma via this region. The increased photon flux density has the further advantage of producing a closer Lambertian light output.

remote opening

Referring to FIG. 17 , an apertured lamp system 173 includes a bulb 175 enclosed in reflective ceramic material 177 except in the area of an aperture 179 . A tapered light tube (TLP) 181 is aligned with the opening 179 . Preferably, aperture 179 is slightly larger than the narrow end of TLP 181, allowing TLP 181 to be overfilled with light. TLP 181 includes a structure 183 on the larger end of TLP 181 that defines a remote opening 185 separate from bulb 175 . In this lamp construction, the structure 183 is essentially part of the light collecting container.

In operation, some light rays A exit lamp system 173 through remote aperture 185 while other light rays B pass through structure 183 and reflect back into bulb 185 via TLP 181 . A portion of light B reflected back to the bulb is redirected by reflective material 177 and exits bulb 175 as light A that exits the lamp system. Also, through proper selection of filling materials (e.g. molecular emitters such as sulfur or indium halides), part of the light B re-entering the bulb 175 is absorbed by the filling material and re-emitted as light A leaving the lamp system, thereby further improving system efficiency. Other advantages provided by the structure 183 forming the remote aperture compared to lamp systems employing the aperture 179 as the lamp system aperture include:

1) The material used to form the structure 183 of the opening has a large selection range. For example, structure 183 may be made of highly reflective metal (e.g., polished on the side of structure 183 facing bulb 175), a dichroic coating, or other highly reflective material;

2) Separate the optical requirements for the aperture 185 from the thermal requirements for the bulb - since the aperture 185 is far from the bulb 175, it will not have as much heat as the area around the aperture 179;

3) system openings can be precisely formed - metal and dichroic mirror fabrication methods may be more precise and repeatable than comparable ceramic fabrication methods;

4) better optical alignment is possible; and

5) Better Shape Use - As shown in Figures 12-24, the optics and remote apertures can take a variety of shapes and sizes. However, a single aperture lamp can use several different optics to meet the level requirements of different systems. For example, the same aperture lamp can be coupled to a round optical fiber or a rectangular liquid crystal display (LCD) image gate by modifying the optics to have the desired remote aperture shape.

Referring to Figure 18, an aperture lamp system similar to the system described above, except that the optical element is a compound parabolic concentrator (CPC) 187 with members 189 forming remote apertures 191 . The CPC187 can be solid or hollow and is usually made of a non-conductive material such as quartz. For example, member 189 is a mirror with portions removed (eg, drilled or machined) to form an aperture 191 . The mirror is attached to the end of a solid CPC with an optically clear adhesive. The mirror can be made, for example, from highly polished sheet metal. Alternatively, member 189 is a transparent quartz disc on which a pattern of dichroic coatings is deposited to form apertures 191 . The disk is attached to the hollow CPC with an optically clear adhesive surrounding the edges of the CPC. Alternatively, an optical holder is designed to position the reflective structure 189 at the end of the optical element 187 .

In FIGS. 19 and 20, the optical element of the present invention comprises a frustoconical TLP having a circular cross-section perpendicular to the axis of the TLP and forming an opening at one end of the TLP which is aligned with the TLP near the light source. opposite to that end. The remote opening can take any desired shape. In FIG. 19, the remote aperture is rectangular, while in FIG. 20, the remote aperture is circular.

In Figs. 21 and 22, the optical element of the present invention comprises a TLP in the shape of a truncated pyramid having a rectangular cross-section perpendicular to the axis of the TLP and constituting an aperture. In Figure 21, the remote aperture is oval. In Fig. 22, the shape of the remote opening is a star or any imaginable opening shape.

In Figure 23, the optical element of the present invention comprises a cylindrical rod light guide forming a remote aperture. The light guide shown is cylindrical. However, those skilled in the art will understand that the light guides may be of any useful shape, including guides having a constant rectangular cross-section or prismatic light guides.

Figure 24 is a perspective view of a CPC constituting a remote port of the present invention. In a light guide or TLP type optic, the light undergoes several reflections against the wall of the optic before exiting the remote aperture or reflecting back to the lamp. In contrast to TLP, in CPC-type optics, most of the light undergoes only one reflection on the walls of the CPC (in each direction) before exiting the remote aperture or reflecting back to the lamp.

In Figure 24, the reflective members on the end face of the CPC constitute a plurality of remote apertures. Such configurations are useful, for example, in applications where optical fibers are used to distribute light. In the configuration shown, the two larger remote openings are coupled to the fiber optics of the vehicle's headlights, while the smaller remote openings are coupled to the optical fibers of the brake lights and/or interior lighting.

Although several examples of optical elements of the present invention have been described and illustrated, those skilled in the art will appreciate that remote-opening optical devices with remote openings for use in combination with apertured light systems can be constructed in accordance with the principles of the invention disclosed herein. Apertures for many other optical elements (such as lenses). Therefore, the aforesaid optical systems are only used for illustration rather than for limiting the present invention. Given the benefit of this specification, many other optical systems are suitable for use with the various aspects of the invention.

Plane source of polarized light

According to one aspect of the present invention, a planar source of polarized light comprises a configuration employing transmissive and reflective polarizing elements (the first is polarization transmitting, the second is reflecting), wherein the polarizing elements are planar rather than curvilinear (eg not spherical), a lens close to the polarizing element.

The general problem is to generate a planar source of uniform polarized light from a planar source of inhomogeneous light at large angles (such as an aperture lamp) while preserving etendue very close to reality. A particular problem overcome by this aspect of the invention is increasing recycled polarized waste light.

For larger angles, the light output of the aperture lamp described here decays faster than the Lambertian cos(θ) curve. The light produced was about 70 to 90% of what would be expected assuming a Lambertian source and using normal light intensities (perpendicular to the source and centered on the source).

However, light from the aperture approaches the Lambertian to about 70 degrees from the normal, and light beyond the maximum Lambertian angle can be reflected back into the aperture for reuse. This is denoted "etendue recycling".

Referring to Figures 25-26, this aspect of the invention is similar to the example of Figure 5, except that the spherical lens is omitted, and a lens (such as a plano-convex lens) is used in cooperation with the polarizer to increase the reflected polarized waste light that can be efficiently recovered amount. The polarizer/lens is combined with a spherical mirror with a central opening to reflect unwanted angled light back into the bulb opening.

A spherical or curved polarizing element is required to reflect the unwanted polarization back into the aperture. However, curved polarizing elements are relatively complex and costly. With a planar polarizing element, most of the reflected light that does not need to be polarized does not re-enter the aperture. Advantageously, the plano-convex lens employed in accordance with this aspect of the invention reflects reflected light from the polarizer back into the source aperture, thereby increasing the amount of waste light that is recycled. Fit a lens or polarizer into the center opening of the mirror. Bulb aperture area adjusted to preserve initial alpha value (for no mirrors or polarizers). This aspect of the invention can be used in combination with a spherical lens, with appropriate adjustment of the dimensions of the central aperture, polarizing element and lens.

Referring to Fig. 26, the center of curvature of a spherical reflector 193 is positioned at the center of the bulb aperture plane (aperture exit plane), thereby forming an inverted aperture image in the bulb aperture plane. The central aperture of the spherical reflector, on the first pass (neglecting error angles and deviations), will define the limiting angular output of light from the apertured bulb. A reflective planar polarizer 195 is placed in the plane of the spherical mirror opening. A plano-convex lens 197 is placed just below the reflective surface of the polarizer, and its focal length makes the light from the bulb opening reflect from the polarizer and the light passing through the lens for the second time will be imaged on the opening. Polarizers can be bonded to the planar side of the lens (if heat is available), can also be formed on the planar side of the lens, or can be separated from the Fresnel non-reflective coating on each optical surface. The amount of light reflected from a polarizer depends on the angle the polarizer subtends and its reflectivity.

Bulbs with integral polished stem and angled opening

In accordance with this aspect of the invention, a ported bulb having an integral light rod has reflective ceramic material beveled near the junction of the bulb and the rod to avoid distracting light entering the rod.

Referring to FIG. 27 , a light system includes a light bulb 215 encased in a reflective ceramic sheath 217 and an integral cylindrical rod-shaped light guide 213 (which may be solid or hollow). Light generated in bulb 215 leaves the lamp system via light rod 213 . Outside the jacket 217, the light is effectively propagated downwards by the total internal reflection of the rod 213. However, the light is scattered when it encounters the interface between the ceramic material 217 and the rod 213, as shown by the lines and arrows in FIG. 27 . A substantial portion of the light entering the rod 213 cannot travel out of the lamp system.

Referring to Fig. 28, this aspect of the invention solves this problem by slanting the ceramic material 217 near the junction of the bulb 215 and the stem 213 at an angle θ so that the beveled surface 219 of the casing 217 does not contact the stem. In this way, light that encounters the wall of the rod 213 near the junction of the bulb 215 and the rod 213 does not encounter the interface with the reflective material 217, and a larger portion of the light travels downward by the gross internal reflection of the rod.

light bulb with integral lens

According to this aspect of the invention, an electrodeless bulb is provided with an integral first optical element. Advantageously, this aspect of the invention eliminates two optical interfaces and one thermal interface.

Certain lamp systems described here and also disclosed in the '940 text show the use of spherical lenses or other optical elements in close proximity to apertured lamps. In these configurations, the surface of the bulb and the entrance surface of the optic provide two optical interfaces, each of which suffers from Fresnel reflection losses. These surfaces can be treated with anti-reflective coatings to reduce losses, but such coatings must withstand the high temperature of the bulb, which also adds cost and complicates the manufacturing process. Another problem with these configurations is that the air space between the bulb window and the optics provides insulation that heats up the bulb window, potentially limiting the operating range of the bulb or the lifetime of the lamp system.

The present invention overcomes these problems by integrating the first optical element with the bulb. Referring to FIGS. 29-30 , an electrodeless bulb housing 221 includes a body portion 223 and an optic portion 225 . Body portion 223 and optical portion 225 are integrally connected, may be integral, and together form enclosed volume 227 . In the preferred illustrated example, bulb 221 has a cross-section similar to that of a human eye, with an optic having a flat entry surface 231 and a frusto-spherical lens in general shape.

Bulb 221 may be constructed of quartz, poly-crystalline alumina, sapphire, or other suitable light-transmitting material capable of withstanding the high operating temperature of the bulb. A preferred example is constructed as follows.

1) Starting with a spherical quartz bulb, a solid quartz rod is welded to the bulb.

2) Heat the soldered area, push the quartz rod in and flatten the inside of the bulb to form the surface of the optic.

3) Using a quartz lathe, place a torch on the rod at a suitable length away from the bulb, heat the rod, and stretch it to form the curved outer surface of the optical portion of the spherical lens.

4) When the optical part has the desired shape, trim off the excess rods and fire polish the trimmed area of the optical part.

The light bulb constructed above was then characterized using an optical collimator. An example bulb identified with approximate dimensions of 9.0 mm in diameter for the body portion, 10.3 mm for overall length along the optical axis and 2.8 mm for the thickness of the optical portion along the optical axis (radius of curvature of 3.4 mm) was Enclosed in a reflective ceramic sheath with 6mm diameter openings as shown in Figure 30. The relative light intensity distribution of the bulb of this aspect of the invention is flatter over a beam angle of +/-30° compared to a spherical bulb in a similarly constructed reflective envelope.

Advantageously, since the optic is integral to the bulb, there are no Fresnel losses in directing light through the optic. Another advantage is that the air gap between the bulb and the first optical element is eliminated.

Molded Optics with Integral Positioning Elements

Various optical elements such as lenses, TLPs, rods and CPCs can be used to guide the light exiting the apertured bulb. Reliable positioning and alignment of optical components in an optical system is difficult. Usually, such elements must be precisely positioned relative to the optical axis and also relative to the aperture. However, pins or mounts that touch the surface of the optic can cause light loss. A variety of optically clear adhesives are available alternatively, but their use adds cost, complicates the assembly process, and can shorten the lifetime or reliability of the system.

This aspect of the invention overcomes these problems by providing a molded optical element with integral positioning elements that can easily interface with other mechanical and/or optical devices without degrading the optical pathway.

Figure 31 shows a truncated spherical lens that can be used in conjunction with apertured lamps for many optical systems. The entry surface is usually much larger than the opening from which light is emitted, so the sides of a spherical lens can be beveled because no light passes through that part of the lens. 32-33 illustrate a molded spherical lens according to this aspect of the invention. The spherical lens is integral with an integral flange near the entry surface and has two keyways 233 and 235 . As noted above, there is no light beyond the 45° cone, and the shape of the molded lens outside of this region has no optical effect. Advantageously, the flange and keyway are located outside of this area so as not to impair the optical function of the lens.

Referring to Figures 34-35, an example of how to make a molded spherical lens is as follows. A solid quartz rod is heated to soften and the softened quartz material is collected at one end. The rod with aggregate material is placed into the two mold parts A, B and the mold is closed around the material. For example, one mold part B forms the spherical part of the lens and one side of the flange, and the other mold part A surrounds the quartz rod and forms the other side of the flange. The thickness of the flange is formed by the groove formed between the two mold parts. In the preferred illustrated example, the grooves provide excess volume for the collective material to flow in, allowing the perimeter of the flange to be arbitrarily shaped. Softened quartz flows around pins placed in one or both of the molds to form the two keyways 233 and 235 . Alternatively, other positioning features may also be employed in the molding process. Although the preferred embodiment utilizes a two-part mold, more than two-part molds can be used as long as due care is taken to avoid forming seams in the optical channels. For example, the mold portion surrounding the quartz rod may be two pieces separated along the centerline that may be placed radially around the rod.

After the lens is molded onto the end of the rod, the rod is cut off in place near the flange to provide the entry surface for the lens. The entry surface can be polished to the desired finish.

Referring to Figures 36-37, a molded ground and axisymmetric solid quartz optical element has a flange at the output end. Its shape is roughly parabolic-conical (eg conical near the input, parabolic thereafter). In this particular use, the smaller diameter end is called the input and the larger diameter end is called the output.

The integral flange provides a place to mechanically mount the CPC, which uses total internal reflection (TIR) for its optical performance. This is an optical component that relies on TIR to receive light input from the bulb opening and then deliver that light to a target or optical element at a controlled size and angle.

Since the CPC relies on TIR, any contact with the surface will constitute a loss, and the flange is located at the output, minimizing the loss due to the small angle of incidence of the light at the output. The shape of the flange is the result of the machining and manufacturing process, and an attempt was made to minimize secondary grinding operations.

The axisymmetric cross-section of the CPC consists of five features, a flat input end face 241, a straight section 243 forming a conical section of revolution, a parabolic section 245 forming a parabolic section of revolution, associated flanges 247 and a flat output 249 . The straight and parabolic segments are optimally controlled to receive light from a given angle of incidence and emit light at another desired angle of incidence.

Subsequent grinding and/or polishing of the input and output surfaces is often required.

Referring to Figures 38-39, a molded optical element has the shape of a TLP with an integral flange at the output end of the TLP.

Tapered Light Cone with Angled Steps

The object of this aspect of the invention is to provide for the conversion of light from near a planar or near-planar light source with high angular radiation to a larger area disk-shaped light source with limited angular range, while preserving etendue more closely than other methods and total light while presenting a lower cost solution than compound parabolic refractors.

A problem with using refractive compound parabolic quartz concentrators is that such concentrators are expensive. However, cheaper and simpler quartz cones do not achieve the desired results. Referring to Figures 40-41, this aspect of the invention employs one or more angular steps in a cone of light to approximate the performance of a refractive compound parabolic concentrator. The individual angles and positions of these steps are preferably chosen to approximate a refractive compound parabolic concentrator that can be replaced by a stepped cone.

Tapered light cones with angular steps are cylindrically symmetrical and can be solid or hollow. The choice of the length and angle of these steps enables the performance of a refractive compound parabolic concentrator to be approximated. The number of steps can be any number from one to as many as are actually required. The example shown in Figure 40 includes two steps. The example of Figure 41 also includes a convex lens on the output surface. The convex lens can be part of a cone, or it can be separated and glued together.

The resulting optics are simple and it approximates a more efficient optical element. The medium or refractive element to be replaced may be parabolic or simply curvilinear. In either case, this aspect of the invention approximates the use of one or more concentrators with straight-sided angular steps, thus having the advantage of ease of manufacture.

Refractive or dielectric concentrators can be fabricated without convex lenses, although the final optic is longer than with lenses.

Truncated Optics

According to this aspect of the invention, a curved or tapered optical element may have four sides which are substantially perpendicular to the output surface of the optical element.

For example, referring to FIGS. 42-44, a non-conductive (such as glass or quartz) solid CPC is trimmed along four dashed lines to form sides perpendicular to the front surface or at small angles so that light is reflected internally, thereby forming the image. The aperture or image aperture light emits within the desired rectangular area. The final optics are shown in Figures 45-47. Referring to Fig. 48, the truncated optic may employ an optional remote aperture screen, preferably reflective on the side facing the output end of the optic, to recycle light striking the screen.

Advantageously, truncated optics can preserve light to a greater extent than other systems in projection systems requiring rectangular image apertures. Medium CPC is well known. In many optical systems, CPC is used in reverse, not to concentrate light, but to shift the angular range of light from a larger value to a smaller value. However, a CPC with a circular output will overfill a rectangular image target, resulting in wasted light. According to this aspect of the invention, a CPC is truncated (eg, cut and/or polished) on four sides so that light is internally reflected from the sides into a more rectangular output shape, thereby reducing the amount of wasted light.

Split CPC

According to this aspect of the invention, an optical element with a curved output surface is segmented more closely to a rectangular image aperture. Advantageously, the segmented optical element increases the amount of light provided from an aperture lamp to a rectangular image object.

As mentioned above, CPCs are common optics for converting larger angle light into lower angle light. However, the CPC is round while the image aperture is rectangular, overfilling the gate and thus wasting light around the perimeter of the object. This aspect of the invention avoids the use of remote apertures and increases the amount of light that can be coupled from the CPC to the rectangular image aperture. Referring to Figures 49-50, a CPC is constructed with four sides. Each side is a smaller portion of the CPC that joins the other sides along its edges to form a relatively rectangular output window. Each side maintains the curve of the CPC to provide the desired angular transformation. The aperture is still overfilled, but with less wasted light.

The segmented CPC can be molded as a single piece or constructed of four segments. The segmented CPC can be solid or hollow. The openings can be round or rectangular. A preferred example of a segmented CPC with a nearly square output has four facets cut from a smaller 25 degree CPC designed for an 85 degree incidence angle. The generally square input face of the CPC may circumscribe a 3.6mm diameter to receive input from a 3.385mm circular aperture. The segmented CPC is approximately 48 mm (1.89 in) long and the output can be circumscribed by a circle of approximately 24 mm (0.94 in).

Optics that bend marginal rays

According to this aspect of the invention, refractive and/or reflective compensating elements are used to match the approach field etendue of a light source to a lens reception etendue. Specifically, an optical element can shift light rays at the edge of the source inward while leaving the inner light rays unchanged.

For example, one aspect of the present invention is to bend light rays inwardly at the edge of the source disk without significantly changing the internal light rays to achieve the desired intensity distribution in the target space in a graded manner.

Referring to Fig. 51, two irises 251 and 253 are used to suppress the angular distribution of light passing through them to a desired range. A lens 255 is configured to bend light rays near the edge of the lens inwardly while leaving unaltered inner light rays in a graded state to better match a target approach field lens reception etendue. Referring to Figure 52, a reflector 257 is configured to bend light rays near the edge of the lens inwardly while leaving the inner light rays unaltered in the graded state.

Double hole etendue selection method and equipment

According to this aspect of the invention, two openings are used to select a desired etendue. For example, one aperture corresponds to the output aperture of an aperture lamp and the other aperture is formed in a reflective spherical (or spherical-like) reflector centered on or near the aperture. The opening of the spherical body forms the entrance of an optical system suitable for holding the etendue formed by the two openings.

Two diaphragms constitute a receiving etendue magnitude (magnitude). A spherical reflector tends (neglecting bias) to reflect light inverted at the center of the sphere. The present invention uses two concepts. The opening through which the lamp emits light corresponds to the first diaphragm. The opening in the reflective hemispherical body corresponds to the second diaphragm. The center of the hemispherical body is located at the center of the hole of the hole-type lamp. In principle, light that does not pass through the second membrane is reflected back to the first membrane (assuming no bias). Therefore, the light passing through the second diaphragm is the etendue that is selected. The spherical body can be changed to reduce misalignment. To reduce misalignment, the spherical reflector can be less than a hemispherical body with its center slightly offset from the lamp opening. The second diaphragm then forms an optical entrance that converts the angle defined by the two diaphragms into an acceptance angle of the target (eg, image aperture), while maintaining etendue.

Referring to FIG. 53 , an apertured lamp 261 constitutes the first diaphragm 263 . A spherical reflector 265 forms a second diaphragm 267 . Beyond the second diaphragm 267, a CPC 269 converts and directs light to further downstream optics. For a given first diaphragm, the reflector 265 performs the function of selecting etendue by setting the radius of the second diaphragm and the length between the two diaphragms. Etendue can be selected according to Lambert's formula:

$\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; \{</span>\sqrt{{\mathrm{<span\; class="notranslate">\; L</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 2</span>}{<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; -</span>\sqrt{{\mathrm{<span\; class="notranslate">\; L</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{<span\; class="notranslate">\; \}</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}$

in

ε stands for etendue;

L represents the length between the two diaphragms;

R1 represents the radius of the first diaphragm; and

R2 represents the radius of the second diaphragm.

For example, for L=6 mm and R1=R2=3 mm, the etendue is 15.2 mm2. Etendue selector 265 and CPC 269 can be made into one part structure. After the etendue selector, an optical element 269 is shown as a CPC, but could also be a compound conic concentrator, a spherical lens or other suitable optical device.

Dual CPC and Integrator

Referring to FIG. 54 (not to scale), a lamp system 271 includes an apertured lamp 273, an angle selector 275 (such as a CPC or a reflective surface such as a CPC), an optical integrator 277 (with an optional angle Amplifier), an optical converter 279 (such as a CPC), an optional reflective/transmissive polarizer 281 and an optional remote reflective aperture 283.

An advantage of an angle selector such as a hollow CPC form or a compound conical concentrator is the ability to return high angle light to the bulb that is not directly used to illuminate the projection display image aperture. Light enters the bottom (major diameter) of the angle selector at angles up to 90 degrees from the optical axis and will pass through the angle selector, or not depending on its angle of entry.

In some configurations, the light exiting the angle selector may not be as uniform as desired. Integrators spatially randomize the light, generally improving uniformity. For example, the integrator may comprise a tunnel integrator in the form of a tube, with a highly reflective inner surface. In general, uniformity improves with increasing integrator length. However, this must be balanced against keeping the optics compact and reducing reflection losses. For a light source with an F-number equal to 1 and a hollow cylindrical tube, a length-to-diameter ratio (relative to the tube diameter) of about 4 or 5 is desired to produce acceptable uniformity. For an F-number less than 1, a smaller aspect ratio is appropriate. Assuming a 4 mm opening, a cutoff entrance angle of 50 degrees, and a hollow tube integrator with a diameter of approximately 3 mm, the integrator length should be less than 10 mm.

There is a trade-off between length-to-diameter ratio, internal reflectivity of the tube, and maximum angle of light entering the integrator. A short angle converter (CPC) added after the angle selector and before the integrator may be required to reduce the integrator input angle from approximately 90 degrees to perhaps 70 degrees. After the integrator, an optical element 279 is shown as a CPC, but could also be a compound conical concentrator (obviously very similar to a CPC), ball lens or other suitable optics.

As mentioned above, the optical device can be made from a single-piece hollow structure. The structure is optionally refractive and preferably A/R coated. Also, the structure may consist of several parts.

Another configuration for angle selector 275 and integrator 277 is an overall conical shape. The first two stages 275 and 277 combine into a very reflective cone with an inclination angle of no more than a few degrees (eg, less than about 2 degrees). A small angle cone of single reflectance will select or limit the angle of light passing through that cone and return the balance to the light source. This confinement is controlled by the inlet and outlet areas of the cone. Since the cone is at a small angle, light traveling along the length of the cone may have many bounces. See "Projection Displays" by Stupp and Brennesholtz (John Wiley 1999), in order for the light to be uniform in the area of the exit disk, the cone should have length L:

$\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}\mathrm{<span\; class="notranslate">\; no</span>}\sqrt{\mathrm{<span\; class="notranslate">\; A</span>}}}{\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; )</span>}$

where L _n represents the normalized length (dimensionless), n represents the refractive index of the medium (e.g. quartz = 1.47 or air = 1), A represents the average cross-sectional area at the average diameter, and _θ represents the intermediate or design cut-off Angle (cutoff angle). For the apertured lamps described here, it is expected that choosing a normalized length close to 5 will result in a uniformity greater than 90%. As an example (quartz cones with end diameters of 2.5 and 3.4 mm):

$\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; 1.47</span>}<span\; class="notranslate">\; \&CenterDot;</span>\sqrt{\mathrm{<span\; class="notranslate">\; \&pi;</span>}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2.95</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}{\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 47</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; \&ap;</span>\mathrm{<span\; class="notranslate">\; 26</span>}\mathrm{<span\; class="notranslate">\; mm</span>}$

In other words, this example of an initial diameter of 3.4 mm, a final diameter of 2.5 mm and a length of 26 mm results in a uniform distribution on a circular plane of diameter 2.5 mm at the end of the cone. The slope of the cone for this example is just under 1.0 degrees.

The cone can be a solid medium or hollow (air), in both cases reflectivity is key. In the dielectric case, light escapes if it is less than the inner critical angle that occurs for returning light (~42.9° for quartz relative to normal). A medium designed to be highly internally reflective (close to unity for interior angles from 0 to 43 degrees to the surface normal) coating the outside of the cone should reduce the amount of escaping light.

For hollow cones, there is also no critical angle. For angles from close to 0 degrees (for return rays) to close to 90 degrees (direct rays), the reflectivity relative to the normal to the surface of the cone should be as high as possible and practical.

Referring to Figures 55-58, various methods of mechanically mounting the separate parts of the angle selector, integrator and CPC are shown. According to this aspect of the invention, the mechanical assembly of the optics can reduce the tolerances of the multi-part hollow angle selector 281 (in the form of a CPC), integrator 283 (solid or hollow) and hollow CPC 285 .

In Figure 55, locator pins 287 are used to position the integrator relative to the other components. However, light loss occurs at the portion in contact with the pin. The diameter of the integrator is larger than the output aperture of the angle selector and the corresponding input aperture of the CPC. The surface of the CPC touching the integrator can be reflective to recycle light. This allows for looser tolerances.

In Figure 56, the outlet of the angle selector is beveled to limit the integrator to within 6 degrees of motion without a pin. Bevel the angle selector instead of the CPC to reduce light loss. In FIG. 57 both the angle selector and the integrator are beveled to avoid damage to the surface of the angle selector (coated) due to line contact when fabricating the structure of FIG. 56 . In Fig. 58, the angle selector includes a flange 289 (eg, a countersink) that confines the integrator.

Referring to Figures 59-60, there are two pairs of single-piece CPC/CPC-like hollow reflective optics 291, 293 and an integrator 295. CPCs are hollow with internal reflective surfaces. For example, the reflective material is a multilayer dichroic coating designed for a suitable range of angles and wavelengths. The mechanical interface of each CPC between the CPC and the integrator constitutes a curved surface 291a, 293a (in the form of a small CPC) respectively.

The small CPC291 at the inlet end of the integrator serves two purposes: 1) Mechanical retention of the integrator, and 2) Reduces the max input angle of the integrator from 90 degrees to an angle that a practical AR coating can achieve, say 50 or maybe 60 degrees . The small CPC 293a at the outlet end of the integrator has its primary purpose as a mechanical holder. At both ends, the CPC must represent a complete design at the contact circle, not extended or truncated, in order to maintain maximum telecentric light through the optical system. The small CPC293a on the outlet side may be shorter (less angular transition) than on the inlet side.

Optical System Example

According to this aspect of the invention, unwanted or unwanted polarization and/or unwanted light outside of the desired skew/etendue is reflected back into apertured lamps (of the type described in the '940 publication) , so that part of the unwanted light is randomized and re-emitted as useful light. Advantageously, the total amount of useful light is increased. This aspect of the invention may be used, for example, in projection displays requiring a polarized light source.

In apertured lamps of the type described in the '940 publication, a bulb is enclosed in a reflective ceramic material except for the area of the aperture. A portion of the light reflected back to the bulb is directed by the reflective material to leave the bulb as useful light. Also, with proper choice of fill material (eg molecular emitters such as sulfur or indium halide), a portion of the light re-entering the bulb is absorbed by the fill and re-emitted as useful light, thereby further increasing system efficiency.

Referring to Figure 61, an optical system 303 includes a compound parabolic concentrator (CPC) 305 with an anti-reflection (A/R) coating 307 at its small end. For normal angles of incidence (0°) conventional A/R coatings are optimal. According to one aspect of the invention, the coating 307 is configured to better combine light having a high angle of incidence with light exiting the aperture. For example, A/R coating 307 is configured for angles of incidence between about 30° and 55°, with a half angle of about 40° being preferred.

The CPC 305 further includes a structure 311 at its large end, which forms a remote opening. When combined with an aperture lamp, structure 311 is essentially part of the light integrating container. In operation, some rays of light A exit optical system 303 through the remote aperture, while other rays of light B are reflected by structure 311 and return to bulb through CPC 305 . As mentioned above, some of the light B reflected back to the bulb is then directed by the reflective material and exits the bulb as light A exiting the optical system. Some of the light B re-entering the bulb is absorbed by the fill and re-emitted as light A leaving the optics.

Optical system 303 also includes a reflective UV (ultraviolet) blocking filter 309, which prevents UV light from damaging downstream components. Optical system 303 also includes a reflective polarizer 313 . Both unwanted UV light and unwanted polarization are reflected back to the lamp to be recycled through the fill. For example, reflective polarizer 313 is made from Dual Brightness Enhancement Film (DBEF), available from 3M.

Referring to FIG. 62 , an optical system 315 includes CPC 305 with A/R coating 307 and remote aperture 311 . Optical system 315 also includes a high angle A/R coating 317 on the large end of CPC 305 . Light from the CPC 305 is directed to a polarizer cube 319 (with sides polished for total internal reflection) with a UV reflective coating 321 on the side of the cube 319 facing the CPC 305 . Light of the desired polarization is reflected by cube 319 through an A/R coating 323 to suitable optics (eg lens 325). Unwanted polarized light is reflected by a visible reflective coating 327 through the CPC 305 back to the bulb.

Referring to FIG. 63 , an optical system 331 includes a CPC 305 with an A/R (anti-reflection) coating 307 . Optical system 331 also includes a CPC holder or flange 333 that fits over the large end of CPC 305 . For example, CPC 305 is made of quartz (refractive index about 1.46), and flange 333 is a quartz disc attached to CPC 305 with an optional transparent adhesive, having a similar refractive index. An A/R coating 335 is provided on the end of the flange 33, not attached to the CPC 305. An air interface (refractive index 1.00) is provided between the flange 333 and the lens 337 . The lens 337 has a reflective UV coating 339 followed by a reflective polarizer 341 . Other optical elements such as cubes can follow behind the polarizer 341 .

Projection system with modulated light source

According to this aspect of the invention, a projection system includes an electrodeless light source and a shutter that can be opened and closed to project an image, wherein power for the electrodeless light source can be modulated according to the opening and closing of the shutter to improve efficiency.

Referring to FIG. 64 , a projection system 351 includes an electrodeless light source 353 that illuminates a frame of film roll 355 to project an image through film aperture 357 . With conventional movie projectors, the film aperture includes a shutter that closes when the film advances between two image frames. The off time represents a substantial portion of the projector's operating time. When the shutter is closed, no light reaches the screen, and the light during the closed period is wasted. According to the present invention, an electrodeless light source is used in the projection system, which can be modulated synchronously with a shutter on the film window, so that there is a strong light output when the shutter is open, and a relatively weak light output when the shutter is closed, thereby Improves the efficiency of the projection system. For example, the light source is modulated at 32 Hz corresponding to 32 image frames per second.

Advantageously, the modulation of the electrodeless light source does not have any negative effect on the lifetime of the light source. Modulation of electrode arc lamps shortens lamp life. Small bulb sizes (eg, 1 cm or less) are desirable in terms of the response time characteristics of the plasma relative to the modulation frequency.

This aspect of the invention is also applicable to LCD (Liquid Crystal Display) or other projection systems that have interrupted states between image frames.

Polarizer Cube and Mirror Structures

This aspect of the invention relates to a novel P/S assembly. Referring to FIG. 65 , an optical system includes a light source 401 that provides light directed toward a polarity separator cube 403 . The light of the first polarity directly passes through the cube, and the light of the other polarity is reflected to a surface of the cube perpendicular to the light of the first polarity. A polarization rotator 405 (eg, a quarter wave plate) is disposed on the surface receiving the reflected light and rotates the polarity of the reflected light to be the same as the first polarity. The light with the rotated polarity is then reflected by the opposing faces of the cube and directed by a mirror 407 to combine with the original light of the first polarity.

Additionally, referring to Figure 66, the polarization rotator may include a half wave plate 409 which passes light directly through the plate rather than reflecting the light back through the cube. In this configuration, the mirror 407 is placed close to the half-wave plate 409 .

Advantageously, large amounts of light can be provided for applications requiring polarized light.

Optical Holder with Cutout Cover

Unlike arc discharge lamps, the apertured lamps described herein are capable of providing a substantially planar light source with an aspect ratio matched to the desired image plane (eg, optical aperture). Therefore, the aperture plane is required to be precisely aligned with the image plane, thus requiring an alignment as follows:

1) No sideways movement up and down or left and right;

2) The aperture plane is perpendicular to the optical axis (parallel to the image plane); and

3) The aperture plane is not rotated around the optical axis.

According to this aspect of the invention, an optical holder meets these requirements. Referring to Figures 67-70, an optical holder 411 provides a hollow tube 413 with flanges 415, 417 at each end. Lenses and other optical components are mounted within the tube with spacers, threaded retaining rings, and the like. One flange 417 is formed with a recessed shoulder 419 for mating with a structural member 421 on the escutcheon. In particular, the aperture cover may be provided with features related to the orientation of the aperture, and the flange may cooperate with those features to enable proper positioning of the aperture relative to the downstream optics. Another flange 415 includes a structural member 425 for mating with a application-specific housing to maintain the aperture plane of the aperture mask in a proper orientation relative to the application-specific image plane.

In the preferred example shown, the aperture shield includes a flange with a straight edge parallel to one side of the aperture. Likewise, the recess in flange 417 is also made as a truncated circle with flat edges to match the aperture mask. The other flange 415 includes a raised rectangular lip 425 with one side configured to be parallel to the flat edge of the recess. Preferably, the optical holder is constructed as a single casting to reduce cost and maintain high precision in the relative orientation between the recess and lip. Advantageously, the single cast optic holder 411 provides parallel surfaces and a mating fit without the need for adjustment mechanisms, alignment pins, or reference marks.

With the structure described above, lateral movement between aperture and image plane, misalignment of plane rotation and clocking rotation are avoided, no further adjustments are required, and through the casting (and aperture mask) Machining precision guarantees high precision.

RF (radio frequency) choke in lens tube

According to one aspect of the invention, an optical holder cooperates with an RF choke to reduce electromagnetic interference (EMI). Referring to Figures 71-74, an optical holder 431 (eg, a lens tube) has an entry side 433 mountable against an RF-energized light source. Depending on the operating frequency of the light source, the narrowest opening in the lens tube may not adequately block RF emissions and unwanted EMI may occur. According to one aspect of the invention, a conductive screen 435 is positioned between the optical holder and the light source to improve EMI suppression. The mesh size is chosen according to the operating frequency of the light source and also to minimize light blocking.

In the preferred example shown, the RF choke comprises a metal mesh sandwiched between two flat metal rings 437a, 437b which provide good electrical contact and increase the stiffness of the metal mesh. The optical holder forms a shoulder 439 adapted to receive an RF choke such that the metal mesh is recessed in the holder. When the optical holder is mounted to the light source, the RF choke is held securely in place.

light box

Fluorescent lamps are typically housed in troughs having standard dimensions of 2 feet by 2 feet or 2 feet by 4 feet. Such recesses are suitable for fitting in suspended ceilings with metal lattices of similar dimensions.

Such fluorescent lighting is relatively efficient, but has only minimal acceptable light quality.

There is a need for a lighting fixture that is a direct replacement for such fluorescent fixtures, but has superior lighting characteristics.

Generally speaking, the lamp cap houses an apertured bulb which directs the output light through a spherical lens, all of which are described in detail in the aforementioned '302 PCT application. With a suitable filling (such as indium halide), the color rendering index of the light provided by the lamp exceeds 90.

Figure 75 is a perspective view of a housing for a light box of the present invention. A housing 515 can be, for example, a standard 2x2 fluorescent light well, which can be purchased at any lighting store. The groove 515 includes a hole 517 on one side. The light output from the lamp head 507 passes through the hole 517 .

Figure 76 is a perspective view of a lens used in the light box of the present invention. The light from lamp head 507 is fairly evenly distributed with a full beam angle of about 140°. The lamp head 507 includes a spherical lens that further collimates the light output uniformly (eg, about 60-70° full angle). According to the invention, the light beam is shaped to more evenly distribute the light into the light box. For example, the lens 519 of a groove 515 consists of a cylindrical lens configured to focus light more narrowly along an axis corresponding to the depth D of the light cell than along an axis corresponding to the width W of the light cell. A suitable cylindrical lens is available from Melles Griot, Irvine, CA, part number 01LCP127. The cylindrical lens further collimates the light output to a full angle of about 24° in only one dimension (eg depth D). Other light box configurations benefit from other beam shaping lens configurations.

Fig. 77 is a cross-sectional view of the light box of the present invention. A light box 521 includes a housing 515 forming an opening 517 . A light source (eg, including lamp head 507 ) is positioned to pass light through opening 517 . An optical system, such as a spherical lens and cylindrical lens 519, is configured to receive light from lamp head 507 and shape the beam to more evenly distribute the light to the light box. For example, a set of brackets 523 may be provided to hold the lens 519 in place.

Typically, a light diffusing cover is placed over the groove 515 . Various reflective and/or diffusive materials are placed inside the recess 515 to alter the light output, if necessary or desired. For example, either or both sides of the light box on the side of the opening 517 and the side of the light box opposite to the opening 517 may be covered with a highly reflective material such as Mylar. Aluminum sheet, a flexible material with a highly polished mirror finish is also available. A similar small piece (eg, 75 mm by 125 mm) of material may be positioned on the bottom surface of the recess 515 proximate to the opening 517 . A diffusive material may be used to reduce the appearance of bright spots, especially near the opening 517 .

The power and RF components can be fixed outside the recess 515 (eg, hidden in the ceiling part). Alternatively, these components may be additionally placed in the ceiling in close proximity to lamp head 507 to provide RF energy in a coaxial cable.

Advantageously, the light boxes described above can be used in standard suspended ceiling grid structures to directly replace standard fluorescent light fixtures. The above configuration of the present invention can be easily extended to standard 2x4 grooves. If necessary or desired, a lamp head can be provided at each end of the recess. Light boxes of other sizes are also possible.

Although a few examples of the optical systems of the present invention have been described and illustrated herein, those skilled in the art will recognize that many other similar systems can be constructed in accordance with the principles of the invention disclosed herein. Accordingly, the foregoing optical systems are given by way of illustration and not limitation. Many other optical systems may employ aspects of the present invention, given the benefit of this description. The invention has been described in connection with what is presently considered to be the preferred embodiment. It is to be understood, however, that the invention is not limited to the disclosed embodiments, but on the contrary, the invention covers various modifications and equivalent constructions within the basic spirit and scope of the invention.

Claims (9)

1. an optical projection system, it comprises:

One light source;

One by the image fenestra of light illumination; And

One shutter that selectively is opened and closed, with from image fenestra projects images,

Wherein according to the opening and closing modulated light source of shutter,

With this light source of shutter synchronization ground modulation, make the light that when shutter is opened, produces projects images export, and when shutter close, produce the light output weak than the light output of projects images.

2. optical projection system as claimed in claim 1 is characterized in that, light source is an electrodeless light source.

3. optical projection system as claimed in claim 1 is characterized in that, light source is an arc lamp.

4. optical projection system as claimed in claim 1 is characterized in that, comes from liquid-crystal apparatus from image fenestra image projected.

5. optical projection system as claimed in claim 1 is characterized in that modulating frequency is corresponding to picture frame frequency.

6. method of operating optical projection system, this method comprises:

Light from light source is provided;

Use optical illumination image fenestra from light source;

Between opening and closing, change the state of shutter, with from image fenestra projects images; And

State modulated light source according to shutter; Modulated light source comprises:

When being in open mode, shutter provides from the light output of light source with projects images; And

When being in closed condition, shutter provides from the weak light output of the light output than projects images of light source.

7. method as claimed in claim 6 is characterized in that the closed condition of shutter is corresponding to the closed condition between the image frame.

8. method as claimed in claim 6 is characterized in that, from image fenestra image projected from from liquid-crystal apparatus.

9. method as claimed in claim 6 is characterized in that modulated light source comprises:

With modulation of source in frequency corresponding to picture frame frequency.

Images